Pembina: The Hidden Elephant

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In a large oil company, the pursuit of oil is a co-operative undertaking of geologist, geophysicist, economist, exploration manager, and top man­agement, who make the ultimate selection of proposed exploration and drilling programs. It was in this manner that Nielsen participated in a rank wildcat, Socony-Seaboard Pembina No.1, 70 miles southwest of Edmonton in a wilderness of pine, spruce and muskeg, pockmarked by a few isolated farms. It was one of the first ventures for Nielsen's new Edmonton district and it could easily have missed becoming the discovery well for Canada's biggest oil field.

The venture involved a farmout of 100,000 acres of government petro­leum reservation rights from the Seaboard Oil Company of Delaware. In return for drilling a deep wildcat well to an estimated depth of 9,400 feet, Socony would earn a half interest in the reservation. The proposed well site was on a suspected anomaly which had been mapped by seismic explo­ration, 16 miles from the nearest previously drilled well. It was a S200,000 gamble in which the odds-as with any wildcat-were at least 10 to one against an oil discovery.

Final decision to drill the well was made at Socony's head offices in New York, based on the recommendations of the Calgary and Edmonton offices. Nielsen had participated in the farmout negotiations with Seaboard, had recommended drilling the well, and had prepared the geological prognosis.

A geological prognosis is a guide prepared for the drilling of every wild­cat. It attempts to blueprint unknown rock conditions thousands of feet below the surface, based upon the best available geological and geophysical knowledge, deduction, intuition and guesswork. The prognosis outlines the rock formations expected to be penetrated in the hole, the estimated depth at which each wiII be penetrated, and characteristics of the for­mations. It indicates which formations should be drilled through, and from which formations cores should be recovered for detailed study. Without a geological prognosis, a wildcat would be no more than a shot in the dark.

In the six years following the Leduc discovery, exploration had yielded a string of prolific Devonian reef discoveries in Alberta: Redwater, Bonnie Glen, Golden Spike, Wizard Lake, Stettler, and several others. From Edmonton, the major pipeline systems were already carrying Alberta oil across most of the continent: east across the prairies to Ontario and south into the United States; southwest across British Columbia to Vancouver and the U.S. Pacific Northwest.

Comparatively few tests, however, had been drilled in the deeper part of the Alberta basin west of Edmonton where exploration costs were high due to almost impenetrable muskeg and forest, as well as the greater drilling depths to the Devonian reefs.

Pembina No. 1 was to evaluate all prospective zones down to the Devonian Leduc reef. The major oil prospects were considered to lie in the Devonian, and farther up-hole in the Mississippian. Above that, sec­ondary oil prospects were considered possible in the sandstones of the Lower Cretaceous, Jurassic, Viking, and Cardium formations.

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